Method and apparatus for signaling privacy in personal communications systems

A wireless communication system comprising:

• an authentication center (AUC) which produces a signaling cipher key and a random number, and stores the random number on a SIM card;
• a wireless communication device comprising a signaling key generator for retrieving the random number from the SIM card and generating the signaling cipher key from the random number, and using the signaling cipher key to generate a signaling cipher key stream used to encrypt signaling data resulting in encrypted signaling data;
• and
• a gateway which receives the cipher key from the AUC, and uses the cipher key to decrypt the encrypted signaling data received from the wireless communication device through a first logical channel;
• and
• a satellite coupled to the wireless communication device by an RF link,
• said wireless communication device further comprising a traffic key generator for generating a traffic key stream, a traffic encryptor for encrypting traffic data with the traffic key stream, a multiplexor for multiplexing the encrypted signaling data with the encrypted traffic data, and a transceiver for transmitting the multiplexed data over the RF link to the satellite, the encrypted traffic data being routed to a called or calling party through a second logical channel.

A method for securely communicating signaling data from a wireless communication device to a first destination device of a satellite communication system, and communicating traffic data to a second destination device, the method comprising the steps of:

• generating a signaling cipher key by a signaling key generator using a random number stored on a SIM of the wireless communication device;
• encrypting the signaling data, by a signaling encryptor, using the cipher key resulting in encrypted signaling data;
• encrypting traffic data with a traffic data encryptor using a traffic cipher key stream;
• multiplexing the encrypted signaling data and the encrypted traffic data for transmission to a satellite of the satellite communication system;
• transmitting the encrypted signaling data over a first logical link to the first destination device, the first logical link comprising a first set of physical links;
• transmitting the encrypted traffic data over a second logical link to a second destination device, the second logical link comprising a second set of physical links,
• wherein the first and second sets of physical links comprise a common RF link between the wireless communication device and the satellite.

A wireless communication system comprising:

• an authentication center for producing a signaling cipher key and a random number and stores the random number of a SIM card;
• a gateway which uses the signaling cipher key to decrypt encrypted signaling data, the encrypted signaling data being produced by a wireless communication device using the random number from the SIM card;
• a satellite communication node coupling the wireless communication device to the wireless communication system by an RF link,
• wherein multiplexed data comprising encrypted traffic data and the encrypted signaling data is received by the satellite from the wireless communication device, the encrypted traffic data being produced by the wireless communication device using a traffic cipher key that is different from the signaling cipher key, the encrypted traffic data being routed over a first logical link through the wireless communication system to a traffic destination node, the encrypted signaling data being routed over a second logical link through the wireless communication system to the gateway.